Finding the Fourth Proportional to 13,146.72, 19,722.48 and 4,380.80

Step by Step Solution

1. Step 1: Write the proportion equation
   13,146.72 : 19,722.48 = 4,380.80 : x
2. Step 2: Convert to fraction form
   13,146.72/19,722.48 = 4,380.80/x
3. Step 3: Cross multiply
   13,146.72x = 19,722.48 × 4,380.80
4. Step 4: Simplify right side
   13,146.72x = 86,400,240.38
5. Step 5: Solve for x
   x = 86,400,240.38/13,146.72
6. Step 6: Final answer
   x = 6,572.00